Insulated bus connection type ring main unit

Abstract

The invention discloses an insulated bus connection type ring main unit, which relates to the technical field of power distribution equipment, and comprises a cabinet body, two main circuit units are arranged in the cabinet body, incoming and outgoing line sleeves are arranged at the bottoms of the main circuit units, the incoming and outgoing line sleeves are connected with a current transformer, and the current transformer is mounted in the cabinet body through a transformer support. And the incoming and outgoing line bushings of the two main circuit units are connected through an insulating bus coupler. The two main circuit units are connected with the insulation bus coupler through the wire inlet and outlet sleeve, the wire inlet and outlet sleeve can be connected with the current transformer, assembly is easy and convenient, construction is convenient, and the functions of phase sequence detection, electricity testing and line protection are achieved.

Description

Technical Field

[0001] This invention relates to the field of power distribution equipment technology, and more specifically, to an insulated busbar connection type ring main unit. Background Technology

[0002] A ring main unit is an electrical device that installs high-voltage switchgear inside a metal cabinet to form a modular ring network power supply unit. It has advantages such as compact structure, small footprint, maintenance-free operation, improved power supply parameters and performance, and power supply safety. It can also switch on / off no-load current, load current and fault current to achieve isolation, control and protection of power transmission and distribution lines, and is widely used in the power distribution field.

[0003] Currently, 10kV ring main units installed in power distribution rooms or basements typically operate with two busbar sections. There are three operating modes: busbar section I operating with busbar section II, busbar section II operating with busbar section I, and busbar sections I and II operating independently. To accommodate the two busbar sections, cables or copper busbars are often used to connect them.

[0004] Cable connections are limited by cabinet distances. For larger cables and narrow cable trenches, the bending radius requirements cannot be met, and the only way to connect them is by lengthening the connecting cables, which is difficult and costly to construct. Copper busbar connections cannot install current transformers, making it impossible to collect signals through current transformers, which in turn causes the protection device to fail due to the lack of effective signal input.

[0005] In summary, how to simplify the construction of busbar connection methods while ensuring line protection functions is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an insulated busbar connected ring main unit, in which two main circuit units are connected by inlet and outlet bushings and insulated bus couplers. It is easy to assemble and construct, and can perform phase sequence detection and voltage testing. In addition, the inlet and outlet bushings can be connected to current transformers to realize the line protection function.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An insulated busbar connected ring main unit includes a cabinet, which contains two main circuit units. The bottom of each main circuit unit is provided with inlet and outlet bushings, which are connected to current transformers. The current transformers are mounted in the cabinet via transformer brackets, and the inlet and outlet bushings of the two main circuit units are connected by an insulated busbar coupling.

[0009] Preferably, the inlet / outlet bushing is fitted onto the central window of the current transformer to achieve series connection between the inlet / outlet bushing and the primary side of the current transformer.

[0010] Preferably, the current transformer bracket includes a base plate and two side plates. The base plate is provided with a through hole for the inlet and outlet bushings to pass through. The side plates are provided with voltage testing holes. The cable of the current transformer is connected to the protection device of the main circuit unit after passing through the voltage testing holes.

[0011] Preferably, the cabinet is provided with a switch compartment and a cable compartment from top to bottom. The main circuit unit is installed in the switch compartment, the current transformer and the insulation bus coupler are located in the cable compartment, and the inlet and outlet bushings protrude from the bottom plate of the air box in the switch compartment.

[0012] Preferably, the current transformer bracket is installed on the bottom surface of the gas box base plate, and the length of the inlet and outlet bushings protruding from the gas box base plate is greater than the height of the current transformer bracket.

[0013] Preferably, the side plate of the current transformer bracket is provided with a waist-shaped hole for installing fastening bolts, and the current transformer is provided with a connection hole for installing the fastening bolts. The waist-shaped hole extends in the height direction of the cabinet to adjust the installation height of the current transformer.

[0014] Preferably, the inlet and outlet bushings are both arranged along the depth direction of the cabinet, so that the insulating bus coupler of each phase is arranged parallel to the cable compartment cabinet door of the cable compartment.

[0015] Preferably, the cable compartment includes a cable compartment door, a side panel, and a rear sealing panel, wherein the cable compartment door and the rear sealing panel are detachably connected to the side panel.

[0016] Preferably, one end of the rear sealing plate is hinged to the side plate on one side via a pivot, and the other end of the rear sealing plate is connected to the side plate on the other side via a locking member.

[0017] Preferably, a sealing ring is provided between the rear sealing plate and the side plate, and the sealing ring is disposed in a sealing groove on the inner surface of the rear sealing plate.

[0018] The insulated busbar connection type ring main unit provided by the present invention connects two main circuit units through bottom inlet and outlet bushings and insulated bus couplers. It is easy to assemble and construct, facilitates phase sequence detection and voltage testing, and the inlet and outlet bushings can be connected to current transformers to realize line protection functions. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a structural schematic diagram of a specific embodiment of the insulated busbar connection type ring main unit provided by the present invention;

[0021] Figure 2 This is a side view of an insulated busbar connected ring main unit.

[0022] Figure 3 This is a structural schematic diagram of the switch room;

[0023] Figure 4 This is a structural schematic diagram of the cable compartment.

[0024] Figures 1-4 middle:

[0025] 100-Instrument Room; 200-Mechanism Room; 300-Cable Room; 301-Cable Room Cabinet Door; 302-Rear Sealing Plate; 1-Live Indicator; 2-Fault Indicator; 3-Electromagnetic Lock; 4-Side Expansion Bushing; 5-Connecting Busbar; 6-Three-Position Mechanism; 7-Circuit Breaker Mechanism; 8-Incoming and Outgoing Bushings; 801-A-Phase Copper Rod; 802-B-Phase Copper Rod; 803-C-Phase Copper Rod; 9-Current Transformer; 10-Transformer Bracket; 1001-Voltage Test Hole; 1002-Oval Hole; 11-Insulating Bus Coupler; 1101-C-Phase Insulating Bus Coupler; 1102-B-Phase Insulating Bus Coupler; 1103-A-Phase Insulating Bus Coupler. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The core of this invention is to provide an insulated busbar connected ring main unit. Two main circuit units are connected by bottom inlet and outlet bushings and insulated bus couplers. It is easy to assemble and construct, and can perform phase sequence detection and voltage testing. The inlet and outlet bushings can be connected to current transformers to realize line protection functions.

[0028] The insulated busbar connection type ring main unit provided by the present invention includes a cabinet, and two main circuit units are provided inside the cabinet. The bottom of the main circuit unit is provided with inlet and outlet bushings 8, which are connected to current transformers 9. The current transformers 9 are installed in the cabinet through transformer brackets 10. The inlet and outlet bushings 8 of the two main circuit units are connected through an insulated bus coupler 11.

[0029] Please refer to Figure 1 and Figure 2 The cabinet contains two main circuit units, each corresponding to a section of the busbar of the ring main unit system. In order to simplify the structure of the ring main unit and reduce the work of paralleling the cabinet, the switch compartment 400 of the ring main unit is usually set to adopt a common gas box structure.

[0030] The main circuit unit includes a side expansion bushing 4, a three-position mechanism 6, and inlet / outlet bushings 8. The side expansion bushing 4 is connected to the three-position mechanism 6 via a connecting busbar 5. The side expansion bushing 4 is the lateral interconnection interface of the main circuit unit. The three-position mechanism 6 is a switching unit used to determine the isolation, grounding, and conduction functions of the main circuit unit. The inlet / outlet bushings 8 are the external electrical connection and insulation protection interface of the main circuit unit. The protection devices, grounding devices, and other functional modules of the main circuit unit are designed with reference to existing technologies according to actual production needs, and will not be described in detail here.

[0031] Both main circuit unit's incoming and outgoing bushings 8 are connected to current transformers 9. Current transformers 9 are connected to the protection device of the main circuit unit. The protection device receives the signal collected by the current transformer 9 and triggers the protection action through electromagnetic lock 3, circuit breaker mechanism 7, etc., to realize the line protection function. In addition, the live display 1 can display the live status of each main circuit unit and prevent personnel misoperation, while the fault indicator 2 can indicate the fault information when a line fault occurs.

[0032] The current transformer 9 can be configured as a busbar through-type current transformer, which has a compact structure, flexible installation, and no need for additional primary wiring, resulting in a low risk of failure; it can also be configured as a winding type current transformer, with reliable primary side connection. The specific type and model of the current transformer 9 are determined according to the actual production needs, such as the maximum operating current of each phase of the main circuit unit, to ensure the safe use of the current transformer 9.

[0033] The current transformer 9 is installed in the cabinet through the transformer bracket 10. The transformer bracket 10 can be connected to the inner surface of the cabinet or to the partition of the cabinet. The connection method between the current transformer 9 and the transformer bracket 10, as well as the connection method between the transformer bracket 10 and the cabinet, is preferably a detachable connection method such as bolt connection or pin connection, so as to facilitate the replacement of the current transformer 9.

[0034] The incoming and outgoing bushings 8 of the two main circuit units are connected by an insulating bus coupler 11. The specific type and model of the insulating bus coupler 11, as well as the connection method between the incoming and outgoing bushings 8 and the insulating bus coupler 11, are determined according to the actual production needs, such as the spatial layout of the ring main unit, the rated voltage of the ring main unit, and the maximum operating current of the main circuit unit.

[0035] Please refer to Figure 4 The A-phase copper rod 801 of the incoming and outgoing bushing 8 of main line unit a is connected to the A-phase copper rod 801 of the incoming and outgoing bushing 8 of main line unit b through the A-phase insulating bus coupler 1103; the B-phase copper rod 802 of the incoming and outgoing bushing 8 of main line unit a is connected to the B-phase copper rod 802 of the incoming and outgoing bushing 8 of main line unit b through the B-phase insulating bus coupler 1102; the C-phase copper rod 803 of the incoming and outgoing bushing 8 of main line unit a is connected to the C-phase copper rod 803 of main line unit b through the C-phase insulating bus coupler 1101.

[0036] In this embodiment, the two main circuit units are connected by the bottom inlet / outlet bushings 8 and the insulating bus coupler 11, which is easy to assemble and construct, facilitates phase sequence detection and voltage testing, and the inlet / outlet bushings 8 can be connected to the current transformer 9 to realize the line protection function.

[0037] For preferred options, please refer to [the following]. Figure 3 and Figure 4 The incoming / outgoing bushing 8 is fitted into the center window of the current transformer 9 so as to realize the series connection between the incoming / outgoing bushing 8 and the primary side of the current transformer 9.

[0038] Compared to wound current transformers, busbar through-type current transformers do not require a separate primary winding, have a compact structure, are easy to install, and are more suitable for installation inside ring main units. Furthermore, the copper conductor rod transmits current to the current transformer 9 through magnetic field coupling, and the current transformer 9 does not bear the mechanical stress of the main circuit unit, resulting in a low failure rate and long service life.

[0039] Preferably, in order to stably install the current transformer 9 in the cabinet, the transformer bracket 10 includes a base plate and two side plates. The base plate is provided with a wire hole for the inlet and outlet bushings 8 to pass through, and the side plates are provided with a voltage test hole 1001. The cable of the current transformer 9 is connected to the protection device of the main circuit unit after passing through the voltage test hole 1001.

[0040] The U-shaped current transformer bracket 10, compared to the L-shaped current transformer bracket 10, is more conducive to preventing the current transformer 9 from shaking inside the cabinet, thus improving the installation stability and reliability of the current transformer 9.

[0041] Based on the above embodiments, the structure of the cabinet is further defined; please refer to [reference needed]. Figure 1The cabinet has a switch compartment 400 and a cable compartment 300 from top to bottom. The main circuit unit is installed in the switch compartment 400, and the current transformer 9 and the insulation bus coupler 11 are located in the cable compartment 300. The inlet and outlet bushings 8 protrude from the bottom plate of the air box in the switch compartment 400.

[0042] Please refer to Figure 1 and Figure 2 The cabinet includes an instrument compartment 100, a mechanism compartment 200, a switch compartment 400, and a cable compartment 300. The instrument compartment 100 is located above the mechanism compartment 200, and the cable compartment 300 is located below the mechanism compartment 200 and the switch compartment 400.

[0043] Please refer to Figure 4 The inlet and outlet bushings 8 are all set along the depth direction of the cabinet so that the insulated bus couplers 11 of each phase are set parallel to the cable compartment cabinet door 301 of the cable compartment 300. Compared with the insulated bus couplers 11 being set at an angle to the cable compartment cabinet door 301, this is more conducive to the installation, replacement and maintenance of the insulated bus couplers 11.

[0044] Preferably, to further facilitate the installation of the insulated bus coupler 11, especially the A-phase insulated bus coupler 1103 near the rear cover plate 302, a cable compartment 300 can be provided, including a cable compartment cabinet door 301, a side plate, and a rear cover plate 302. Both the cable compartment cabinet door 301 and the rear cover plate 302 are detachably connected to the side plate. Removing the rear cover plate 302 can significantly increase the installation space of the A-phase insulated bus coupler 1103, facilitating the installation, maintenance, and replacement of the A-phase insulated bus coupler 1103.

[0045] The connection method between the rear cover plate 302 and the side plate of the cable compartment 300 can be the same as the connection method between the cable compartment cabinet door 301 and the side plate, or it can be different from the connection method between the cable compartment cabinet door 301 and the side plate.

[0046] One end of the rear cover plate 302 can be hinged to a side plate on one side via a pivot, and the other end of the rear cover plate 302 can be connected to the side plate on the other side via a locking element; the locking element can be specifically configured as a locking buckle, etc.

[0047] Alternatively, the rear cover plate 302 and the side plate can be slidably connected via a linear guide rail mechanism, and a locking element is provided between the rear cover plate 302 and the side plate. The locking element is used to fix the relative position of the rear cover plate 302 and the side plate so as to realize the opening and sealing of the rear side of the cable chamber 300.

[0048] Alternatively, the rear cover plate 302 can be connected to the side plate via detachable fasteners such as screws and connecting pins. The connection structure is simple, but the installation and removal process of the rear cover plate 302 is relatively cumbersome.

[0049] Preferably, a sealing ring is provided between the rear sealing plate 302 and the side plate. The sealing ring is located in the sealing groove on the inner surface of the rear sealing plate 302 to ensure the sealing performance of the rear side of the cable compartment 300 and to ensure the overall sealing performance of the cable compartment 300 and even the ring main unit cabinet.

[0050] In this embodiment, the current transformer 9 and the insulating bus coupler 11 are located inside the cable compartment 300. On the one hand, this facilitates the installation of the current transformer 9 and the insulating bus coupler 11, and avoids the assembly, replacement and maintenance of the two from affecting the main circuit unit inside the switch compartment 400. On the other hand, it also facilitates the installation of the transformer bracket 10.

[0051] For preferred options, please refer to [the following]. Figure 4 The current transformer bracket 10 is installed on the bottom surface of the gas box base plate to reduce the installation space occupied by the current transformer bracket 10. The length of the inlet and outlet bushing 8 protruding from the gas box base plate is greater than the height of the current transformer bracket 10, ensuring that the inlet and outlet bushing 8 can be connected to the insulating bus coupler 11 below the current transformer bracket 10.

[0052] Based on the above embodiments, considering that the working state of the main circuit unit will affect the model and size of the current transformer 9, the side plate of the transformer bracket 10 can be provided with a waist-shaped hole 1002 for installing fastening bolts, and the current transformer 9 can be provided with a connection hole for installing fastening bolts. The waist-shaped hole 1002 extends in the height direction of the cabinet so as to adjust the installation height of the current transformer 9, thereby meeting the installation requirements of current transformers 9 at different heights and increasing the applicability of the ring main unit.

[0053] The dimensions of the waist-shaped hole 1002 are determined based on the height range of the current transformer 9 in actual production, so as to ensure that the tallest current transformer 9 can still be smoothly installed in the transformer bracket 10.

[0054] Of course, multiple mounting holes can also be provided on the side plate of the current transformer bracket 10 along the height of the cabinet, and the mounting height of the current transformer 9 can be adjusted by adjusting the position of the mounting holes connected to the current transformer 9.

[0055] Alternatively, the installation height of the current transformer 9 relative to the transformer bracket 10 can be set to be constant, while the installation height of the transformer bracket 10 relative to the cabinet can be adjusted. Or, the installation heights of both the current transformer 9 and the transformer bracket 10 can be adjusted to meet the installation requirements of current transformers 9 at different heights.

[0056] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] The insulated busbar connected ring main unit provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An insulated busbar coupling type ring main unit, characterized by, The utility model provides a kind of current transformer and main circuit unit's installation structure, including cabinet, two main circuit units are equipped in the cabinet, the bottom of main circuit unit is equipped with incoming-outgoing line sleeve (8), incoming-outgoing line sleeve (8) is connected with current transformer (9), current transformer (9) is installed in the cabinet by mutual inductor support (10), the incoming-outgoing line sleeve (8) of two main circuit units is connected by insulation bus tie (11).

2. The insulated busbar link type ring main unit according to claim 1, characterized by The incoming-outgoing line sleeve (8) is sleeved on the central window of the current transformer (9) to realize the series connection of the incoming-outgoing line sleeve (8) and the primary side of the current transformer (9).

3. The insulated busbar link type ring main unit according to claim 2, characterized by The mutual inductor support (10) includes a bottom plate and two side plates, the bottom plate is provided with a threading hole for the incoming-outgoing line sleeve (8) to pass through, and the side plates are provided with electricity testing holes (1001), the cable of the current transformer (9) is connected with the protection device of the main circuit unit after passing through the electricity testing holes (1001).

4. The insulated busbar link type ring main unit according to any one of claims 1 to 3, characterized in that, The cabinet is provided with a switch chamber (400) and a cable chamber (300) from top to bottom, the main circuit unit is installed in the switch chamber (400), the current transformer (9) and the insulation bus tie (11) are arranged in the cable chamber (300), and the incoming-outgoing line sleeve (8) protrudes from the air tank bottom plate of the switch chamber (400).

5. The insulated busbar link type ring main unit according to claim 4, characterized by The mutual inductor support (10) is installed on the bottom surface of the air tank bottom plate, and the length of the incoming-outgoing line sleeve (8) protruding from the air tank bottom plate is greater than the height of the mutual inductor support (10).

6. The insulated busbar link type ring main unit according to claim 5, characterized by The side plates of the mutual inductor support (10) are provided with waist-shaped holes (1002) for installing fastening bolts, the current transformer (9) is provided with connecting holes for installing the fastening bolts, and the waist-shaped holes (1002) extend in the height direction of the cabinet to adjust the installation height of the current transformer (9).

7. The insulated busbar link type ring main unit according to claim 4, characterized by The incoming-outgoing line sleeves (8) are arranged along the depth direction of the cabinet, so that the insulation bus ties (11) of each phase are arranged parallel to the cable chamber cabinet door (301) of the cable chamber (300).

8. The insulated busbar link type ring main unit according to claim 7, characterized by The cable chamber (300) includes the cable chamber cabinet door (301), side plates, and a rear sealing plate (302), and the cable chamber cabinet door (301) and the rear sealing plate (302) are detachably connected with the side plates.

9. The insulated busbar link type ring main unit according to claim 8, characterized by One end of the rear sealing plate (302) is hinged to one side plate via a rotating shaft, and the other end of the rear sealing plate (302) is connected to the other side plate via a locking member.

10. The insulated busbar link type ring main unit according to claim 8, characterized by A sealing ring is arranged between the rear sealing plate (302) and the side plates, and the sealing ring is arranged in a sealing groove on the inner surface of the rear sealing plate (302).

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